Apparatus for cutting tapered filaments



v March 14,` 1 944.

APPARATUS. FOR CUTTING TAPERED FILAMENTSl F'iled Nov. 25, 1942. 2 Sheets-Sheet 1 l5. w. CRANE TAL Y l 2,343,887

4 e aber: TNQ/ds? IWENTORS BY La. QQ/L1 ATTORNEY APPARATUS FOR CUTTINGv TAPERED vF'ILAhMlN'lS Filed Nov. 25, 1942 2 sheets-shea 2 waagi l LILI: I6

76 Paul WC'cane INVENTORS 3 53 4f 7J .Reubecr .Refds 19.9% 'I r- BY 2R31 .9 fw. @1Q/p. l

Arme/vir Patented Mar. 14, 1944 UNITED STATES APPARATUS FOR CUTTING TAPERED FILAMENTS Paul W. Crane, Montclair, and Reuben T. Fields, Arlington, N. J., assignox's to E. I. du Pont de Nemours & Company, Wilmington, Del., a corporation of Delaware Application November 25, 1,942, Serial No. 466,966

12 Claims.

This invention relates to anapparatus for cut-.`

ting tapered filaments and, more particularly, to cutting a filament composed of a series of tapered sections into units of substantially identical length and shape.

In describing the present invention-frequent reference will be made to tapered filaments of synthetic linear polymers because tapered lilaments of these substances are of particular commercial interest but it will be apparent that the invention is applicable to tapered filaments .in general regardless of their particular composition.

Tapered iilaments of synthetic linear polymers are of value in the manufacture of paint brushes and the like, to replace natural bristle, and in, the manufacture of fishing lines and leaders, in which they replace braided textile fibers, silk worm gut, and the like. Inasmuch as the difficulties of cutting tapered filaments to make bristles for brushes are greater than in the case of iishing leaders, where each individual unit is relatively of much `greater length, the invention will be described with particular reference to tapered laments of the former type.

Continuous tapered iilament, composed of a series of tapered sections, must be cut up into individual pieces for use. In the case of shing lines and leaders, in which the length of the unit is considerable andin which it is not essential that the filament be cut with great exactitude at the points of smallest and largest diameters, the problem of cutting into lengths is relatively simple, and the cutting may be done with shears or other simple manual equipment by a reason- A ably trained operator.

But the cutting into lengths of tapered iilament for use in brushes is not readily or ecc` nomically accomplished by such methods. Since the lengths of the individual tapered sections of filament for -this use may be as short as a couple of inches, and seldom longer than about a foot, the number of cuts per pound of material is very large and cutting by manual means, even if it gave satisfactory results, would be prohibitively expensive. Actually, cutting by such methods does not give satisfactory results. If it is left to the operator to determine visually the points of maximum and minimum diameter, at one or both of which the cut must be made, inaccurate cutting is bound to result, since the exact locations of these points cannot be found by simple inspection. If, one the other hand, one point of minimum or maximum diameter be carefully determined as a starting point, and the subsequent cuts be located on the assumption of exact regularity in length of successive units, the result is satisfactory only if the assumption is valid. If the length of the unit deviates, for any reason, from the assumed value, the cut will be mislocated. Inaccuraces, from whatever source, in the cutting of these short lengths are of serious consequence; either the pieces of inaccurate cut will be unacceptable for use, and must be scrapped, or else they must be trimmed Y at one end or the other, or both, with cost'in labor and material, in order to make them acceptable as of a shorter length.

In the present specication, points of maximum and minimum diameter will be referred to. for sake of brevity, respectively as maximum and minimum-points. In iilaments in which the tapered sections are separated by untapered sections of maximum or minimum diameter, the maximum- (or minimum) point is the point midway in the length of such untapered section of maximum (or minimum) diameter. The distance between successive maximum-points, or between successive minimum-points, is designated the unit length of the tapered niament.

Further, with respect to the configuration of the iilament it is to be noted that for commercial success in the important eld of use as bristles in brushes, it is ordinarily desirable that the alternating increases and decreases in diameter along the lament be substantially symmetrical with respect to intervening maximumand minimum-points so that, when the filament is cut at maximumand minimum-points, the resulting individual lengths or bristles will all be identical in length and in shape; those formed during increase in diameter of the filament and those formed during decrease will be substantially indistinguishable. Filament meeting this practical requirement is herein referred to as symmetrically tapered.

The invention will be described in detail primarily with reference to the cutting of symmetrically'tapered filament and with reference to the more usual practice of cutting it at successive maximum-points, but it will be made clear that the invention is not restricted in either of these respects.

It is an object of the present invention vto provide a means of cutting tapered lament accurately into unit lengths. More particularly, it is an object to provide for the accurate cutting of such iilament at points of maximum or of minimum diameter. It is further an object of the invention to provide means of cutting accurately, at successive points of maximum or minimum diameter, or any other predetermined diameter, a filament in which the successive uni-t lengths exhibit minor variations.

It is further an object of the invention to provide, for the accomplishment of tJhese purposes, apparatus which is readily adjusted tothe requirements of filaments of various nominal unit lengths, and which, when soadjusted, will funcnon continuously without attention, Vadjusting itself automatically to minor variations in unit lengths.

The above objects are accomplished according to the present invention by delivering tapered filament to a cutting mechanism and varying the relation between the linear rate of delivery of the filament t the cutting mechanism and the frequency of operation of the cutting mechanism in conformity with the variation in the unit lengths of the tapered filament.

More particularly, tapered filament may be cut according to one embodiment of the apparatus vof the present invention by delivering tapered filament at a constant linear speed to a cutting mechanism and varying the frequency of operation of this cutting mechanism in conformity with' theinterval of time between the arrival of successive maximum points of the filament at aiixed station. It lies equally within the scope of the invention, however, to maintain constant the frequency of the cutting mechanism and to vary the linear speed of delivery of the filament in the same manner, and only minor changes need be made in the apparatus to adapt it to operation under this latter system.

The apparatus for the cutting of tapered filament by the first of these alternative embodiments com-prises, broadly, means of cutting, means of delivering filament at a constant linear speed to the cutting means, means of gauging the diameter of the iilament passing a fixed station in advance of the cutting means, and means, actuated through this gauging means by changes in the diameter of the filament, of altering the frequency of operation of the cutting means.

More specifically, inthis embodiment of the invention, the control and modification of the frequency of operation of the cutting mechanism are accomplished through the cooperation of a gauging device or feeler through which the passage of filament'of more (or less) than a predesignated diameter actuates the closingof an electrical switch and through which the passage of filament of smaller (or larger) diameter actuates the opening of this switch, two alternative electrical circuits in parallel actuating, respectively, means of accelerating and means of decelerating the operation of the cutting means, and a commutator synchronized with the cutting means and serving to complete an electrical circuit between the above switch and, in alternation, the two parallel circuits.

. It is an important feature of the invention that each period during which theswitch is closed is divided, by the action of .the commutator, into a subperiod of acceleration of the cutting means and a subperiod of deceleration of the cutting means, and that, when the filament is of exactly the nominal unit length for which the mechanism has been set, this division takes place at the midpoint of the period, so that the subperiods of acceleration and deceleration are equal. There is then no net change effected in the time elapsing between'successive cuts.

Conveniently, but not necessarily, this coordination of the mechanism is achieved by so synchronizing the commutator and the cutting mechanism that commutation takes place at the instant of the action of the cutting mechanism to cut the filament, and at he same time by so spacing the gauging means from the cutter that,

Other objects of the invention will be. apparent from the description given hereinafter.

when the filament is of exactly nominal unit length, the arrival at the feeler of a point in the filament midway in the length of iilament during which the switch is closed will coincide, in time, with the arrival at the cutter of a `point in the filament at which a cut is to be made.

Thus in the specific case of cutting symmetrically tapered filament at successive maximum points, with the feelermechanism arranged to hold the switch closed during .passage of filament of diameter in excess of a predesignated equal subperiods the period during which the switch is 4in closed position.

Accordingly, the successive accelerating and decelerating effects balance each other, and there results no change in the time between successive cuts. So long as the unit length of the filament is unchanged, successive cuts will occur at Uh'e same desired point in each unit length.

If, however, the unit length of the filament increases slightly, delaying the arrival of a maximum-point at the gauging means, the commutation takes place not at its arrival but before that instant, and the period of contact is accordingly not equally divided; instead. the subperiod of acceleration is shortened and the subperiod of deceleration is lengthened, with the result of retarding A the action of the cutting means to compensate'for the increase in unit length.

Conversely, a shortening of the unit length lengthens the subperiod of acceleration and shortens that of deceleration and thus hastens the action of the cutting means to compensate.

The invention will be disclosed in detail with reference to the accompanying drawings wherein:

Fig. 1 is a plan view of an apparatus in accordance with a preferred specific embodiment of the invention;

Fig. 2 is an elevation of the apparatus shown in Fig. l, looking in the direction of the arrows 2-2 in Fig. 1;

Fig. 3 is a section on the line 3-3 of Fig. 2, in the direction of the arrows;

Fig. 4 is a section on the line 4-4 of Fig.' 2, in the direction of the arrows;

Fig. 5 is a section on the line 5-5 of Fig. 2, in the direction of the arrows;

Fig. 6 is a plan view of the compensator shown diagrammatically in Figs. land 2 in its operating position by reference numeral 56; it is also a section on the line 6-6 of Fig. '7;

Fig. 7 is a section on the line 1-1 of Fig. 6;

Fig. 8 represents diagrammatically the profile of a tapered filament; and

Fig. 9 is a wiring diagram showing the electrical connections between various elements of the apparatus shown in Figs. 1 and 2.

The apparatus and its operation will now be deslcibed, with reference primarily to Figs. 1 an In a device for merely cutting equal lengths,

omitting the matter of cutting a tapered filament at a predesignated point-in each repetition of its profile, a filament I I, coming from the preceding operation or from a storage spool, passes between two pairs of pinch rolls, I2, I3 and i4,

I5, of which the lower members I2 and I4 are driven, and the upper mem-bers I3 and I5 are idlers. Between the two pairs of pinch rolls is aplate I6 pierced by an orifice I1 which is in line with the points of tangency of the two pairs ofv 'to the plate I6 around the orifice II, and the shearing action between the knife 2D and the boss 2I causes the filament II to be cut (see Fig. 5). 'Ihe cut pieces, being already in the grip of the pair of pinch rolls I4, I5, are thus carried away and deposited beyond the pinch rolls I4 and I5.

The mechanism thus far described, together with necessary drives, is all thatis needed to cut continuous filament into short lengths. So long as the peripheral speed of the pinch rolls is uniform and the speed of rotation of the cutting knife also is uniform, the filament will be cut into pieces of equal length. But this simple -equipment makes no provision for the cutting of tapered filament at 'a predesignated point in each repetition of its profile (e. g., at the point of its maximum diameter), nor for making slight variations in the lengths cut, in conformity with slight differences in length between successive units of taper. Apparatus in accordance with the present invention for accomplishing these purposes -will now be described in connection with the cutting of a symmetrically tapered filament at its maximum points.

Before arriving between the pinch rolls I2 and I3, the filament II passes through a gauging device 22 conveniently designated a. feeler and indicated'generally by the reference numeral 22 in Figs. l and 2; Fig. 3 also shows this feeler. The feeler 22 comprises essentially a fixed surface in Contact with which the filamentpasses, a rocker bearing upon the filament during its contact with the fixed surface, and means whereby the rocker arm, when forced away from the fixed surface by-passage of filament of diameter greater than a lpredesig'nated value, causes the closing of an electrical circuit.,

'I'he moving parts of the feeler 22 are m'ounted upon a panel 23, which is attached to a table 24, which supports also certain other parts of the apparatus. Aii'ixed to the panel 23 is a shoe 25 havinga oor curved convexly toward the line of travel of the filament I I.

.The path of the filament may be an uninterrupted straight line tangent to the convex surface of the shoe 25. This would be a horizontal straight line in Fig. 2. But it is preferable to bring the filament II up over the shoe 25 from a slightly lower level, as shown in Fig. 2. The

friction created thereby is negligible and this arrangement not only insures constant contact of the filament I I with the shoe 25 but also avoids the risk of a misalignment in the opposite sense. which would cause an unsupported filament to exert an undesirable lifting action upon the rocker 26, which is next to be described.

This rocker 25 is pivotally mounted above the shoe 25 by means of a pin or screw 21. Desrably there is mounted in -this rocker a wheel 28, adapted to rotate with its lower portionupon the shoe 25. The weight of the rocker 26 and wheel 28 are sufficient to keep the latter in contact at all times with the filament I I passing over the rigid surface of the shoe 25, and thus the motion of the rocker 26 as a lever about the fulcrum 21 is governed by the changes in thickness of the filament II under the wheel 28. In the preferred form of the apparatus, however, which is designed to handle a group of filaments, passing through together, contact of the wheel 28 with the portions of smaller diameter of the passing filament II is prevented by restriction of the downward motion of the rocker 26 by a stop 29 (see Fig. 2). 'This restriction allows the passage through the feeler, without restraint of any kind, of the portions of filament of smaller diameter. and thus gives opportunity for the equalization of tension among the several filaments of the group.

The floor of the shoe will differ in detail in accordance with the manner in which the filament is fed across it. Viewed as in Figure 3, this fioor may be flat and horizontal so thaty in the absence of the stop 29, it would make contact with the wheel 2s across the m11 width of the latter. In this formit serves its function of gauging, by the wheel 28, of a single filament,

or of a parallel group of filaments traveling like a ribbon andall in contact with this fioor; in either such case the distance to which the wheel 28 is raised from the floor of the shoe 25 is merely the maximum diameter of a single filament, and the amplitude of motion of the rocker 26 is correspondingly small, so that delicate adjustment must be made to insure 'that the electrical contact between members 3l and 32, hereinafter described, will occur at the desired instant.

Preferably, for handling filament in multiple, as it is ordinarily produced, the floor of the shoe 25 would be provided with a cut in it, that is, a groove of' such cross-section that the filaments approaching it in phase in a flat ribbon-like group are, upon entering it, crowded together into a compact rope-like bundle. The diameter of this bundle is, of course, several times as great as that-of a single filament, and the resulting multiplication of the difference in diameters at maximumand minimum-points provides a desirably greater amplitude of motion of the rocker 26.

In order that the groove shall adequately serve its purpose of crowding the group of filaments into a compact bundle, the width of the groove will be a fraction, usually less than one half, of the product of the maximum diameter of the filament and the number of filaments in the group. For, onthe assumption that the bundle is circular and that the filaments group themselves in a concentric fashion about one central filament, the fraction will be, theoretically,

For 7 filaments v. 3/1 Foi-19 filaments 5/19 For 37 filaments rl/rrl (cf. Pender, Handbook for Electrical Engineers," second edition, p. 1983) To the panel 23 is attached a bracket 30 of insulating material, and to this are affixed two -resilient electrical contact members 3l and 32,

to which are attached the respective electrical leads 33 and 34. The member 3l is fitted with an insulating knob 35 which,-by reason of the re# silience of the member 3I, remains at all times. in contact with the. rocker 28. The upward and downward motion of the rocker 26 effects, re-

spectively,'closing and opening of contact between the mem-bers 3l and 32. An adjusting screw 36 passing through the bracket 38 land into the panel 23 provides for adjustment of the device by changing the distance between the electrical contact members 3| and 32 in their open position. Details of this assembly are shown to best advantage in Fig. 2.

The compensator 56 is driven from the countershaft 52 through a sprocket 51 which is shown in Figsp and '7. The sprocket 51 isattached to the shaft 58 of the compensator 56 which constitutes its driving shaft. 'I'he shaft 55, already mentioned, is the driven shaft of the compensator 56, and the direction in which it is turned is dependent upon the operation of intermediate mechanism next described.

An intermediate shaft 59 (see Fig. 6) lying between the shafts 58 and 55 is driven by the shaft 58 by way of sprockets 'and chain 68, and carries one half 6Ia of a jaw clutch. 'I'he shaft 58 rotates in the same sense as the shaft 58. Coaxial with the shaft 58 and located near the opposite end of the shaft 58 isa similar shaft 62,

closing them' in synchronization with the cutting action of the knife 28 upon the filament II.

Referring particularly to Fig. 4, to a base plate 38, which is fastened to the table 24, are attached two insulatingy supports 38 and 48. The support 38 carries two alternative contact 'surfaces 4 I' and 42 to which are connected respective leads 43 and 44. `The other insulating support 48 carries a resilient lever member 4,5, through which electri` cal currentl can be carried between a lead 46 and either ofthe contacts 4I and 42. position of the member 45 is in contact with the member 4I, but it can be raised, against its resilience, to break contact with 4I and make contact with the alternative member 42. This alternation of contact is effected by thea-ation of a cam 41 rotating beneath the member 45, to which latter is attached an insulator 48 to prevent its making. electrical contact with the, cam 41. The cam 41V is mounted upon the shaft I9. and is accordingly synchronized with the cutting disc I8, which also is mounted upon this shaft. Figs. 1 and.2 show the position of this commutator 31 with respect to the apparatusas a whole. The method and apparatus ofthe invention are based upon provision of controlled difierentials of speedbetween the pinch rolls, I2, I3, and I4, I5, and the -cutting ,disc I8. The whole system is vdriven by'a motor 48, which is connected by sprockets and chain to the constantspeed shaft 58 of a variable reducing drive 5I. From this shaft 58, by way of a countershaft 52, are driven the pinch rolls I4 and I2 which, therefore, rotate at'constant speed. The shaft I8 is driven, by way of a right-angle drive 53, from the variable-speed shaft 54 of the variable reducing drive 5I. The rate of rotation of the shaft I8 is thus subject to change through ad- `iustment of the ratiobetween the speeds of the shafts 58 and 54 of the variable reducing drive The normal which carries one half 63a of a second jaw clutch. The shaft 62 is driven from the shaft 58 by means of meshing gears 64 and 64a, andhence rotates in the opposite sense from that of shaft 58. The mating halves 6Ib and 63h of the respective jaw clutches are carried on the ends of a shaft 65 which is coaxial with the shafts 58 and 62 and lies between them and is of such length that it can be moved longitudinally between them so as to effect engagement of one or the other of the jaw clutches 6I and 63. Obviously, the shaft 65 must be carried in bearings which will permit its movement longitudinally butl such bearings have been omitted from the drawings to permit clearer illustration of the arrangement of the various parts. Upon the shaft 65 is a gear 66 which meshes with a gear 61 carried by the shaft 455.y Thus, with the shaft 58 in rotation, the engagement of the clutch 6I will `cause the shaft to rotate in sense opposite to that of shaft 58; engagement of the clutch 63, however, will cause the shaft 65 to rotate in the same sense as the shaft 58.

.Refering to Fig. 7, a collarV 68 is carried by the shaft 65 which is free to rotate Within the collar 68. Rings 88 and 8l yiixedly mounted on shaft 65 serve toprevent lateral movement of the collar 68 along .the shaft 65. Pinned to the collar 68 on the shaft 65 is the lower end of an 5I. 'I'his ratio is controlled by the turning of a shafts 58V and 54, which in the ordinary use of a variable reducing drive is accomplished by manual operation of a handwheel, or by a pilot motor, is here provided by automatic-operation of a reversing drive controlling the turning of the shaft 55. 'I'his reversing drive, referred to herein for convenience as a compensator,

is shown diagrammatically in its operating position in Figs. 1 and 2 at 56, and is shown in detail,

on a larger scale, in Figs. 6 and 1.v

armv68, of which thevv upper end is pinned at a kfixed point in. the framev of the compensator,

which frame is omitted from Fig. 7 for purposes of simplification. Mounted upon this arm 68, at right angles to it, are two core-pieces 18 and 1I of magnetizable metal, and to the frame of the compensator are affixed two solenoids12 and 13 in such positions as to be entered by the respective core-pieces 18 and 1I.

The solenoid 12 has two leads 14 and 15 for connection with other parts of the apparatus, and the solenoid 13 has, similarly, leads 16 and 11.

The passage of electric current through the solenoid 13, setting up a magnetic flux to attract the core-piece 1 I, will cause movement of the arm 89 in the direction of the solenoid 13 and thus accomplish the engagement of the two halves 6Ia and 6Ib of the jaw clutch' through which rotation of the shaft 58 will be transmitted to cause rotation of the shaft 55 in the opposite sense. This is the position of the arm 68 and the shaft in the Figs. 6 and '1. Analogously, the passage of electrical current through the solenoid 12 will cause therotation of the shaft 58 to be transmitted to rotate the shaft 55 in its own sense. l

-The cooperation of the feeler 22, the commutator 3 1 and the compensator 56 with each other is shown by the wiring diagram of Fig. 9. In

rigs leeds 1s and Vle represent e convenient source of current, e. g., the lighting circuit. -In

- the rocker 28 and re-establishes the electrical the circuitfmade up of the various elements shown in Fig.,9', current flows only when there is contact betweenthe members 3i and 82 of the feeler 22,'i. e., only when the diameter of the filament II passing over `the shoe 25 and tangent under the wheelv28 isin excess of a. Y

For purposes of illustracross-section of a symmetrically tapered filament represented exaggeratedly in Fig. 8.

When contact exists between 8i and 32, the

current which flows will pass through one or the other of the solenoids 12 amiv 13, according to whether contact of the arm 45 of the commutator 81 is madethrough the circuit 4I, 48 or through the circuit 42, 44.

The angular positions of the cutting disc I8 and the cam 41 on the shaft I9 are such that the transfer of contact in the commutator 81 from the circuit .4I 48, etc., to the circuit 42, 44, etc., by the raising action of the cam 41 upon the strip 48 takes place at theinstan't at which the cutting knife 2li on the cutting disc I8 severs the filament .II emerging through the boss 2-I. 1

If the filament shown in cross-sectional form in Fig. 8 is assumed to be passing from left to right through the feeler 22,and if the latter is adjusted so as to make and hold a closed contact between members 8| ande82 when the diameter of' the filament I I passing under the wheel 28 is in excess of that at the successive points A, it willbe evident that this circuit will be open during the passage of the portion of the lament between A1 and Az, closed during the passage of liz-'A3, open during the passage of A3-A4, and so forth. It is desired that the cut be made at a maximum-point. If the distance between the point of cut at2Il and thepoint of tangency of the filament I I with the wheel 28 of the feeler 22 be n unit 'lengths (where n is a whole number), then when a cut takes place at the maximum-point M1, the point of tangency with the wheel 28 of the feeler 22 will be the maximumpoint n unit lengths away, e. g.,

4at Ms.

contact. But meanwhile, at an instant corresponding to the passage past the point of tangency of the minimum-point ma, i. e., one half revolution of the shaft I9 subsequent to the instant of the cut, the action of the cam. 41 has allowed the contact strip tobreak contact with the circuit 42, 44 and to establish contact with the circuit 4I. 43. Accordingly now when, upon arrival of pointAe at the point of tangency, current is'caused to flow again, it flows this time through the other solenoid I3 and accordingly actuates a rotation ofthe' shaft 55 to reverse the adjustment v.lust made in the ratio of speed between shafts SII and 54, i..e., to accelerate the speed of the shaft I9. Then upon arrival of the point M4 at the point of tangency, the cycle is completed and the switch to the solenoid I2 is repeated. Thus between theinstants of passage of successive maximum-points past the point of tangency, there has been a period of slowing down of the cutting disc I8 (M3-A5), a period of constant Aspeed (Ar-As) and a period of speeding up (Ae-M4).

Since the periods Ma-'Ar and Ae-Mr are equal, the slowing down and speeding up balance each other, and the elapsed time between successive one of which (e. g., Ar-Mr, etc.) the cutter is l -beingeaccelerated and during theother of which time, a gradual change in the ratio of speed between the shafts and v '54 of the variable reducing drive and correspondingly a change (retardation) in speed of the shaft I9 which is driven from the latter. When the travel of the lament II through the feeler 22 carries the point As past .the point of tangency with the wheel 28, the corresponding fall of the rocker 28 breaks the convtact between members 3i and 32, and current ceases to ilow in the solenoid 12. At this instant of the cessation of the pull of the solenoid 12, the

v 'll'he ratio remains. .unchanged until-.the further passage ofthe moment brings the point Ae to the point of tangency with the wheel 28. This raises (e. g., Mei-A3, etc.) it is being decelerated. Under the circumstances just described, vin which the actual unit length is exactly the nominal unit length for which the mechanism has been set, there occur within one revolution oi the cutting' disc I8 one subperiod of deceleration (e. g., Ms-Ar.)y and one subperiod of acceleration (e..g., Aia-M4), and since these subperiods are equal there is no net effect upon the frequency of the cut. So long as the unit length of the lament remains constant, the time elapsing between successive cuts remains constant and each cut is made at a maximum-point as is desired.

If, however, a small change occurs in the unit length, i. e., in the distance between successive maximum-points, as may result from some inadi vertent irregularity in the preceding stepsA of manufacture of the tapered filament, it becomes necessary to make a corresponding change in the time elapsing between the instants of successive cuts, and this change the apparatus automatically accomplishes.

Let it 'b e assumed that the unit length has become longer. Since the linearY rate ot travel of the lament II isunchanged, it becomes necessary to reduce the rate of rotation of the cutting disc I8 in orderthat the distance between'successive cuts shall be increased to thedistance between successivepoints of maximum diameter.

'Assume that a cut is made, as before, at a maximum-point Mr, but that the unit length tangency at the instant of this cut will be not at the point Ma, as before, but instead will be at a point short of this, between A4 and Ms, such l as L.

' It wm be remembered that heretofore during the passage of the filament from A4 to M; under l -shaft'55 and thus duplicates its rotation, either the `4feeler 22 the vcompensator, 56 to acceleratefthe shaft `I of the variable reducing drive; and hence toaccelerate therotation ofthe cuttingl disc I8, andthatv this accelerating. action hascontinued until the instant .of the cut, which directly or, preferably, aia-reduced angular amplitude. Thus the ,successive clockwise and counterclockwise rotations of shaft Y55 are indicated by heretofore has Ltaken place at the instant when M1 is at lthepointof tangency.V Now, however,

with a .greaterjclistance between M2 and Ma, Vthe cut takes zplace=before M3 arrivesat the pointv l0 gency. .1.Since,A however, at'theinstant-of the cut f the commutator 31 acts .toreverse the adjustment. of the speed'of the shaft-54; it will be evident that thisftim thesubperiod ofv acceleration of the of tangency, i. e.;when=L is at thepoint of tanshaft 54 has-beenreduced byan amount corresponding tothe time of travel rofvv the.. distance 1 L-Mm .-Furthermore, this samezlength of :time which.A has Abeen subtracted from the subperiod' of --acceleration of the vshaft5l is .added to the subperiod of its retardation, whichnow covers the time of-travel .of the distance L--As insteadA of lids-.Am This time, thorn-the retarding effect of the-operation `.of'the compensator-is greater. than the accelerating eiect. Furthermore, dur--A ingthe period 7of inactivity.oftheY compensator. during the passage through the feeler.22. of theA clockwise and counterclockwise movements ofthe pointer 88. Behind the pointer is a disc 82` which is fastened, by means of .a clamp 83, to

the table 24. This disc 82 thus does not rotate,`

l and hence two pins 84 and 85 fastened to the faceA of the disc 82 and projecting beyond the plane` of thel pointerl 80 serve as.i points of referencev for observing the motionof thelatte'r.'v These pins 8.4 and 85 are separated by an angular` distance corresponding to about twice the'normal amplitude ofthe oscillations of. the pointer 'tilly corresponding to the alternating rotations of the Under normal conditions of lvariationin unit.

.. length of lamen't the necessary compensation is tial compensating eiectbf the mechanism, andv achieved by something yless thanthe full potencorrespondngly .the 'pointer' seldom is moved to its full amplitude in either direction.V When, l.

however,v a gross variation'in unit length of iila` length As-.Aavthe decreased ratevofrotation of the shaft 54, resulting from the longer :period of yretardation, is'maintained. These two factors,

combine todecrease the average of lthe ,rate of rotation of the shaft 54, and Acorrespondingly to l delay the next arrival of thecuttingknife at` the point. of cut, and thus -to compensate for the` increasein unit length.- of .the filament.

The actionbf the mechanism to compensate of the speed of the cutting ldisc to. compensate for thenormal fluctuations can be set at a desirabl meanfbe'tween s'lluggishness and over? cc'impensa'tionl by suitably' selecting themagnitude of the rate of change imposed by the compensator titupon the ratio ofspeed between thetwoshafts f 58 an`d15il4 ofthe variable` 'reducing gearl 5I This. magnitude is.' ofcourse, a function o f the rate of rotation ofthe shaft 55 and ofthe. length of time of its rotation, and correspondinglyis 'subject to control (l) by selection'oi gear ratios between'th'e shaft gan'd the shaft and (2) by lengthening or shortening the period'of .activity of the solenoidawhich corresponds to the time of traveljoifth' length Ae-As and which is therefore cnitrollableA by setting .the feeler v22, by means of the adjusting screw 35, to close the electricalbircuitunder the actuation `of a smaller or largei'diameter of filament. I t t.

The apparatus of the invention 'is designed 'to menty is encountered.` Qsuch as may result from a;

momentary failure or irregularity ina preceding operation, `or from a splice), the mechanism, being designed only to make delicate compensation forsmall variations, is unable to neutralize itsl effect Within a reasonable time. .This situation is made evident by 'persistent contact of. the

pointer Bllagainst one voftheY pins 84` or 85, and.

some provision must be'made to prevent shearing ofthe pin, or a break v.elsewhere in the nicchanism, at such a time.

This protection is desirably achieved iby providing .ancpporturiity for slippage vbetween the compensator 5B andthe shaft l55 whlch'is driven'` by it. To this end, the gear 61 (Figs. 6 and 7) is not keyed vto the shaft but drives the latter through a friction clutch mechanism. A collar 86 is fastenedv tothe shaft'55 adjacent to the gear 61 in its operating position. Against the other faceof the gearB'I ay bre'disc 81 is held by'a clutch plate 88 vin iderthe i;hrustof ajspring 89 abutting against a second collar 9.0,`which is fastened tojthe shaft 55 in such position as to y create appropriate compression of the spring 8 9.

When the 'occurrence of a Agross change in unit length of filament is evidenced bypersistent contact of the pointer'il with one of the pins 8E or' 35, and by 'slippage ofthe clutch mechanism just describe'cLthe clamp 833s released, allowing the 82'to accommodate itself to the thrust of the ypointer im, so that the clutch mechanism is nolonger caused to slip. With the arrival now at the ieelerZZ of filament of normal unit length,

vthe compensating mechanism, freed of the re"- f straint rof the pinsfi and 85, will within a 'few compensate for'minorvaigiations in the' unit cycles' eect a restoration" of the necessary coincidence of arrivall of the knife '20 and a maximum-point, of the filament I i at the point of cut. Then the pointer 80 is returned to its normal operating position, and with it the disc 82', which is then clamped againI into position.

l' It willbe'understood -that the apparatus de' scribed above and shown in'y the drawings is mere ly illustrative and that the invention is .not lim-v I itedthereto.V A fundamental of the specinc ap` paratus' illustrated andof-the invention resides in varying the relationV between the linear rate of delivery of lament to a cutting mechanism and the frequency'of operation ofthe latter. The

' rate of delivery of the filament is constant and the frequency of the cutter is varied in the spe- .-and the instant ofV cut,

y cific apparatus illustrated. However, itis en- A tirely feasible to maintain constant the frequency of cutting and to vary the rate of delivery of the filament.

To do this involves simple mechanical changes inthe ymechanism described, e. g., driving the cutting' disc I8 from the constant-speed shaft 50,

driving the rolls I2, I3, I4, I and the commu- The period auring'whieh the e1ectrica1 circuit r An advantage of the present invention is that it provides a practical and automatic means by f which tapered nlament may be accurately cut f at a desired point ineach successive unit length.

A further advantage' is that the apparatus of this invention automatically accommodates it-4 self to minor variationsin successive lunit lengths is closed has been described above as embracing the time of passage through the feeler of lament of diameter labove a predesignated value (e. g., At-As) and the instant of cut as occurring, normally, at the midpoint of this period. Obviously the purposes of the invention will be equally well servedby having the circuit closed, instead,I during the period of passage of filament of less than predesignateddiameterfe. g., As-Ae) and having the instant of cut occur, normally, at the midpoint of that period. vSimple electrical and mechanical changes in the mechanism as described enable it to function in this equivalent manner.

If it be desired to cut a. symmetrically tapered filament at successive minimum-points instead of maximum-pointsthe change is effected by moving the feeler 22 so that Athe distance between its point of tangency, under the wheel 28, and the point of out at shall be (n4-V2) unit lengths. If it should be desired to make the cut elsewhere than at a maximumor minimum-point, this could -be accomplished by suitable chan'ge in the position of the feeler 22.

For purposes of simplifying the description of the invention and thereby facilitating the understanding of it, it has been stipulated in the foregoing .detailed description that the filament involved is of symmetrical taper, and that 4the synchronization of the commutator and the cut- -ting mechanism is such that commutation takes place at the instant of cut. But an understanding of the inventionin that specific embodiment will make it evident that it is not restricted'in either of these respects.

Even if the taper is not symmetrical, it will stillact to raise and lower the rocker and thus to provide alternating periods i-n which the switch is closed and openedl In the case of nonf-symmetrically tapered filament, the midpoint of the period in which the switch is closed will usually` not coincide with the maximumor minimumi point. But if the feeler be so placed that the coincides with the instant of commutation, the desired result is obtained. Thus in this variant it is necessary merely that the feeler have been moved 'slightly to one side or the other of the position n or (n4-t) unit lengths from the point 'of cut.

' .will be evident that, regardless of the time reinstant of commutation merely an appropriate. the distance between feeler and lationship between the adjustment of cutter is required to insure that the cut will oecu'r'at the desired point in the unit length.`

of tapered filament. A still further advantage is that the present inventionl accurately cuts a plurality of tapered filaments simultaneously;

in fact, itactually accomplishes thisl just as effectively, if not more effectively, than it does when only a single filament is being cut.

As many apparently widely different` embodi` ments of this invention maybe made without departing from the spirit'and scope thereof', it is to be understood `that the invention is not limited to the specific embodiments thereof except as defined in the appended claims.

We claim:

" l. In an apparatus for cutting a tapered filament composed of a series of relatively uniform tapered sections, at a predetermined point in each of said tapered sections, the combination of means for cutting a tapered filament, means for deliveringl said filament to said. cutting means, a gauging device comprising a rigid surface and a rocker adapter to make tangential contact with filament in contact with said lsurface at a fixed point in the path of said lament in ad- Vance ofsaid cutting means, and means actuated through 'said gauging device by change of diameter of the 4filament there gauged, of controlling the relationbetween the linear rate of delivery of saidfilament and the frequency of operation of said cutting means.

2. In an apparatus for cutting a tapered filament composed of a series of relatively uniform tapered sections, at a predetermined point in each of said tapered sections, the combination of a rotating knife for cutting a tapered filament, means for delivering said lament at constant linear speed to said rotating knife, means for gauging the diameter of said filament passing a fixed station in advance of said rotating knife,

' and means actuated through said gauging means instant of tangency of this midpoint normally by change of diameter of the filament there gauged, of controlling the speed of the rotating knife and correlating said speed with the frequency of change of diameter of said filament. 3. In an apparatus for cutting a tapered lilament composed of a series of relatively uniform tapered sections, at a predetermined point in each of said tapered sections, the combination of means for cutting a tapered nlament, said means operating at uniform frequency, means for delivering said filament to said cutting means, means for gauging the diameter of said iilament passing a nxed station in advance of said cutting means, and means actuatedthrough said gauging means by change of diameter of the lament there gauged, of controlling 'thelinear rate yof delivery of said filament to `said cutting means and correlating said rate with the frequency of change ofv diameter of said filament.'

4. In an apparatus for cutting a tapered filament composed of a series of relatively uniform tapered sections, at a predetermined point in each of said tapered sections, the combination of means for cutting a tapered filament, means for delivering said filament to said cutting means,

a gauging device comprising a fixed rigid surface and "a rocke'riadapted to make tangential contact with nl t in contact with said surface at a fixed point thepath of said filament in advance of said cutting means, an electrical Y switch actuated by the displacement of said rocker by a cha-nge in diameter, beyond a predesignated value, in said filament passing in contact therewith, two alternative electrical circuits, means in one of said alternative circuits of increasing the ratio between the frequency of operation of said cutitng means and the linear rate of delivery of said lament to said cuttingA means, means in the other of said alternative circuits of decreasing said ratio, and a commutator synchronized with said cutting means and adapted to complete an electrical circuit between said switch and, in alternation, each of said alternative circuits. l

5. In an apparatus for cutting a tapered lament composed of a series of relatively uniform .tapered sections, at a predetermined point in each of said" tapered sections, the combination of means for cutting a tapered filament, means for delivering 'said lament at constant linear speed to said cutting means, a gauging device comprising a fixed rigid surface and a rocker adapted to make tangential contact with filament in contact with said surface at a xedpointin the path of said filament in advance of said cutting means, an electrical switch actuated by the displacement of said rocker by a change in diameter, beyond a predesignated value, in said filament passing in contact therewith, two alternative electrical circuits, means in one of said alternative circuits of accelerating the frequency of operation of said cutting means, means in the other of said alternative circuits of decreasing said frequency, anda commutator synchronized with said cutting means and adapted to complete an electrical circuit between said switch enfil in alternation, each of said alternative circui 6. In an apparatus for cutting a tapered filament composed of a series of relatively uniform tapered sections, at a predetermined point in each of said tapered sections, the combination of means for cutting a tapered lament, means for delivering said lament to said cutting means,4

a gauging device comprising va xed rigid surface and a rocker adapted to make tangential contact with filament in contact with said surface ata i'lxed point in the path of said filament in advance of said cutting means, an electrical switch4 actuated by the displacement of said rocker by a change in diameter, beyond a predesignated value, in said filament passing in contact therewith, two solenoids in alternative electrical circuits, a commutator synchronized with said 'cutting means and adapted to complete an electrical circuit between said switch and, in alternation, each of said solenoids, a variable reducing drive having a constant-speed shaft driving said means for delivering said filament to said cutting means and having a variable-speed shaft driving they said synchronized cutting means and `commutator, and a reversing gear driven by said constant-speed shaft and driving the adjustment shaft of said variable reducing drive, the reverses of said gear being actuated by the alternate energizations of said solenoids.

7. In an apparatus for cutting a tapered filament composed of a series of relatively uniform tapered sections, at a predetermined point in each of said tapered sections, the combination of a rotating knife for cutting a tapered filament, a pair of pinch rolls fordelivering said filament to said rotating knife, means for gauging the diameter of said filament passing a fixed station in advance of said rotating knife, and means ac-4 tuated through said gauging means by change of diameter of the filament there gauged, of controlling the relation between the speed of the 5 pinch rolls and the speed of the rotating knife.

8. In an apparatus for cutting a tapered filament composed of a series of relatively uniform tapered sections, at a predeterminedpoint in each of said tapered sections, the 4combination of a rol0 tating knife for cutting a tapered filament, a pair of pinch rolls driven at constant speed for delivering said filament to said rotating knife, means for gauging the diameter of said filament 'passing a fixed station in advance of said rotating knife, and means actuated through said gauging means by change of diameter of the filament there gauged, of controlling the speed oi' the rotating knife .and correlating said speed with the frequency of change of diameter of said 2o filament.

9. In an apparatus for cutting a tapered filament composed of a series of relatively uniform tapered sections, at a predetermined point in each of said tapered sections, `the combination of a rotating knife for cuttinga tapered filament, a pair of pinch rolls for delivering said filament to said rotating knife, a gauging device comprising a xed rigid surface and a rocker adapted to make tangential contact with filament in contact with said surface at a fixed point in the path of said filament in advance of said rotating knife, an electrical switch actuated by the displacement of said rocker by a change in diameter, beyond a predesignated value, in said fila- 35 ment passing in contact therewith, two alternative electrical circuits, means in one of said a1- ternative circuits of increasing the ratio between the speed of said rotating knife and the speed of said pinch rolls, means in the other of said alternative circuits of decreasing said ratio,

.anda commutator synchronized with said rotatlng knife and adapted to complete an electrical circuit between said switch and, in alternation, each of said alternative circuits.

10. In an apparatus for cutting a tapered filament composed of a series of relatively uniform tapered sections, at a predetermined pointin each of said tapered sections, the combination of a rotating knife for cutting a tapered filament, a pair of pinch rolls driven at constant speed for delivering said filament to said rotating knife, a gauging device comprising a xed rigid surface and a .rocker adapted to make tangential contact with filament in contact with said surface at a fixed point in the path of said filament in advance of said rotating knife, an electrical switch actuated by the displacement of said 'rocker by a. change in diameter, beyond a predesignated value, in said filament passing in contact therewith, two alternative electrical circuits, means in one of said alternative circuits of accelerating the speed of said rotating knife, means in the other of said alternative circuits of decreasing said speed, and a commutator synchronized with said rotating knife and adapted to complete an electrical circuit between said switch and, in` alternation, each of said alternative circuits.

11. In an apparatus for cutting a group of like tapered filaments composed of a series of relatively uniform tapered sections, at a predetermined point in each of said tapered sections, 'the combination of means for simultaneously cutting a group of like tapered filaments, means for delivering said group of filaments to said cutting means. a gauging device positioned in the path of said group of filaments in advance of said cutting means, said gauging device comprising a iixed rigid surface provided with a groove through which said group of filaments pass, the width of said groove being less thanv half of the product of the :maximum diameter of an individual filament and the number of laments in said group, and a rocker adapted to make tangential contact with said group of filaments in said groove in contact with the door thereof, and means actuated by the displacement of said rocker by a change in diameter, beyond a predesignated value, in said ianrents passing in contact therewith, of controlling the relation between the linear rate of delivery of said group of laments and the frequency of operation oi said cutting means.

12. In anapparatus for cutting a group of like tapered laments composed of a series of relatively uniform taperedsections, at a predetermined point in each of said tapered sections,

the combination of means for simultaneouslyk cutting a group oi' like tapered laments, means for delivering said group of iilaments to said cutting means, a gauging device positioned in the path of said group oi! filaments in advanceof said cutting means, said gauging device comprising a xed rigid surface convex toward the path of said group of filaments and provided with a groove through which said group of laments pass, the width'of said groove being les than half of the product of the maximum diameter oi.' an individual iilament and the number of filaments in said group, and a rocker adapted to make tangential contact with said group of iilaments in said groove in contact with the oor thereof, and means restricting the'approach of said rocker to the floor of said groove, and means actuated by the displacement of said rocker by a change in diameter, beyond a predesignated value, in said iilaments passing in contact therewith, of controlling the relation between the linear rate of delivery of said group of filaments and the frequency of operation of said cutting means.

PAUL W. CRANE. REUBEN T. FIELDS. 

